1. Field of the Invention
The invention relates to turbojets, whose high pressure compressor is equipped with stiffening disks on the inner face of its rotor. The function of such disks is to compensate for the radial stresses supplied by the blades or blade assemblies of the rotor fixed to the outer face of the latter.
2. Prior Art and Set Problem
With reference to FIG. 1, the rotor 2 of a high pressure compressor 1 of a turbojet has blades 4, whose function, in conjunction with the blades 5 of the stator 6, is to compress the air flow within the reactor before supplying it to a combustion chamber 7. This rotor 2 also has a downstream exhaust cone 8 narrowing with respect to the axis 10 of the rotor 2.
With reference to FIG. 2, a prior art exhaust cone 8 essentially comprises a first conventional disk 9, perpendicular to the rotor axis 10 and having at its end a fly-weight 9A. In the same way, in the center of the conical portion 11 of said cone 8, there is a second conventional disk 12, which is surmounted by a fly-weight 12A. In general terms, said second conventional disk 12 is less wide than the first conventional disk 9.
These conventional stiffening disks 9 and 12 serve to prevent rotor deformation, i.e. a deformation of its upstream ferrule 13 and of the conical outlet portion 11. Thus, under the effect of the centrifugal force, the rotor blades tend to be drawn towards the exterior thereof. The conventional disks 9 and 12 make it possible to balance said force by creating an internal inertia, more particularly due to their respective fly-weights 9A,12A. Thus, the latter are placed on radii which are much smaller than the rotational axis of the rotor 10 compared with the root of the blades on the ferrule. This compensation phenomenon is symbolized by vertical arrows in opposite directions designated F.
The disadvantage of these conventional disks 9 and 12 is that they have a relatively high weight, mainly due to their fly-weights 9A,12A. In addition, in FIG. 2, it is possible to see in mixed line form the displacement of the exhaust cone during the operation of the engine. Thus, it undergoes both a widening and an elongation in the downstream direction.
The object of the invention is to attempt to reduce the weight of the rotor, while preventing deformations due to the blade assemblies.